Clickers:

Clicker1.jpg

Clickers are easy for students to use; it can also easily involve every student to answer the pre-selected questions in a relaxing way. For teachers, Clickers are an excellent tool to evaluate students’ level, interest and opinion in a real time manner. It is good for self introduction, student interest evaluation, review and preview.
http://www.einstruction.com/elqNow/elqRedir.htm?ref=http://www.einstruction.com/support_downloads/files/win/CPS_Web_6.56.0058.exe

Video Instructions or Written Instructions to administer clicker question

Advice on using Clickers - Part 1
Advice on Using Clickers - Part 2